EBC Newsletter June 2013, Issue 57 1

02 ECBCS TranSformEd To EBC 06 finanCing EnErgy

rEnovaTion of ExiSTing BuildingS

03 living and Working in ThE fuTurE

issue 57 | June 2013

EBC nEWS

09 ToTal EnErgy uSE in BuildingS 11 miCro-gEnEraTion

in BuildingS

EBC is a programme of the international Energy agency (iEa)

13 EmBodiEd EnErgy and Co2

2 EBC Newsletter June 2013, Issue 57

Cover pictures - Top: application

and testing of aerogel based high

performing rendering. Bottom:

historical building renovated with

aerogel based rendering. Source:

Empa, Switzerland

Published by AECOM Ltd on behalf of

the IEA EBC Programme. Disclaimer:

The IEA EBC Programme, also known

as the IEA Energy in Buildings and

Communities Programme, functions

within a framework created by the

International Energy Agency (IEA).

Views, findings and publications of the

EBC Programme do not necessarily

represent the views or policies of the

IEA Secretariat or of all its individual

member countries.

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Services Unit (ESSU), c/o AECOM Ltd

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© 2013 AECOM Ltd on behalf of

the IEA EBC Programme

ECBCS Transformed to EBC

It is my pleasure to announce that our international re-search and development programme has adopted a new name and a new logo. We are now known as the IEA 'Energy in Buildings and Communities' Programme, or EBC for short. Alongside these changes, the EBC Execu-tive Committee has approved new designs for the news-letter, the Annual Report and the website, which have been created by a talented young Swiss designer. This renewal of our identity has been one of my first initia-tives as the Committee Chair and is certainly the most visible. Since the EBC Programme was founded in 1977, the logo had remained substantially unchanged. The Com-mittee felt that this now symbolized out-of-date tech-nologies and did not capture the full scope of our work. So, it was decided the new logo should represent not only small houses, but also larger buildings and com-munity scale technologies. We believe the new logo meets these requirements, in which the circle enclosing the buildings symbolizes communities. In addition, the logo’s style fits well with that of the IEA R&D Network, enhancing communication and the shared identity.Beyond the Executive Committee’s wish to create a new logo, it was considered to be important to simplify both our full name and our acronym to help to increase the prominence of the Programme. 'Energy in Buildings and Communities' was selected, because it retains the main keywords of the Programme and concisely ex-plains our focus. As a consequence, these enhancements in communica-tions naturally led to a redesign of our reports and web-site to present a coherent identity. With the help of my Executive Committee colleagues and the strong support of our secretariat. I am therefore pleased this task is now complete. What you are holding in your hands (or reading on your screen) is the result - I hope you like it. Our commitment to high impact technology research and development for energy conservation in integrated building and community systems remains unchanged.

Andreas Eckmanns

EBC Executive Committee Chair

EBC Newsletter June 2013, Issue 57 3

While buildings account for about 45% of total prima-

ry energy consumption and 40% of all energy-related

carbon dioxide (CO2) emissions in Switzerland, exist-

ing research findings show there is huge room for

improvement in these areas. Indeed, various national

and international strategies are already calling for

our building stock to undergo a thorough makeover

according to sustainable development criteria.

At a national level, two rather different visions have

emerged about the long term goal for reductions, both

of which were developed in the ETH Domain. Energy

efficiency is central to the first idea, the '2000-Watt

Society'. This concept requires global primary energy

use to be reduced by 2100 to a level equivalent to a

continuous consumption of 2000 Watts per person.

To place this in context, in 2010 average energy con-

sumption in Switzerland was 6500 Watts per person.

The second idea, the 'One-Tonne-CO2 Society', allows

for less extreme energy demand reductions, as long

as the differences can be offset by renewable sources

of energy supply. The main aim would be to reduce

long-term total CO2 emissions per person to below one

tonne per year.

Living and Working in the FutureBuildings Energy Research in Switzerland

Andreas Eckmanns

Double vision usually needs correction, but not for Switzerland. They have created two ambitious yet convergent visions for their future energy system and have challenged their buildings research community to respond.

2000 2080206020402020 2100

10

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2000 2080206020402020 2100

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kW p

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year

Vision “2000-Watt Society”

Vision “One-Tonne-CO2 Society”

reduction patterns in these two models will be similar in the immediate future. at the end of the century both strategies would lead to emissions of one tonne Co2 per person, albeit with differing energy requirements. Source: Swiss federal Energy research Commission CorE

Different ways of reducing primary energy requirements and CO2 emissions: visions of a 2000-Watt Society and of a One-Tonne-CO2 Society

4 EBC Newsletter June 2013, Issue 57

renovation of an apartment block with prefabricated elements. Source: EmpaThe EBC project 'annex 50: Prefabricated Systems for low Energy renovation of residential Buildings‘, led by Switzerland, developed innovative solutions for the efficient renovation of apartment blocks.

National energy policyIn 2008, the climate change policy for Switzerland was

set with the goal of reducing domestic CO2 emissions

to 80% of 1990 levels by 2020. In 2011, the Federal

Council decided to continue to maintain Switzerland's

high level of electricity supply security even with the

phasing out of nuclear energy in the medium term. To

guarantee supply security in the future, the Federal

Council is focusing on increased energy efficiency, the

expansion of hydropower and use of new renewable

energy supplies, and, where necessary, on fossil fuel

based electricity production (combined heat and pow-

er plants, gas-fired combined cycle power plants) and

imports. Furthermore, expansion of Switzerland's

electricity networks to accommodate these changes

is underway and energy research is to be intensified.

To address these key areas in terms of research and

development (R&D), the Federal Energy Research

Masterplan has been established. This Masterplan

defines four focus areas which essentially cover all

aspects of energy research. They reflect everyday

life and our everyday energy requirements. The four

focus areas are also recognised in other countries as

the main ways of improving efficiency and reducing

CO2 emissions. These are:

– 'Living and Working in the Future'

– 'Mobility of the Future'

– 'Energy Systems of the Future'

– 'Processes of the Future'

The buildings-related R&D priorities are defined with-

in the focus area 'Living and Working in the Future'.

Living and Working in the FutureThe vision of the research focus area 'Living and

Working in the Future' points towards energy efficient

and near emissions free ways of living and working:

It states that in the future the majority of the Swiss

building stock should no longer produce pollutants

and greenhouse gases. In fact, buildings should be

important contributors to distributed energy genera-

tion and should collectively produce approximately

the amount of energy required to meet heating and

electricity needs in our daily lives. To achieve this

vision, this focus area has initiated research into tech-

nologies and concepts involving energy requirements,

energy conversion, energy use and local generation

of renewable energy in individual buildings, groups

of buildings, neighbourhoods, towns and whole cities.

Because cost-benefit analyses highlight the need for

EBC Newsletter June 2013, Issue 57 5

different solutions where old and new buildings are

concerned, Switzerland is faced with a number of dif-

ferent challenges: For existing buildings, energy con-

sumption should be considerably reduced and at the

same time converted to 'carbon-neutral' operation,

in which CO2 emissions are avoided by local genera-

tion of renewable energy. New buildings should not

generate any polluting emissions. In future, emissions

generated during building construction and the sub-

sequent disposal of construction materials should be

considerably less than at present.

To achieve this, the research community needs to

develop technologies and concepts by which energy

can be generated, converted and used intelligently

in buildings. This includes both technological and

socio-economic research. The findings must then be

translated into products, planning and implement-

ing instruments, and subsequently transferred to the

market.

Public funding of energy related R&DIn Switzerland public funds for energy-related R&D

cover a total amount of 220 million Francs per year

(around 180 million Euros per year). More than half

of this is allocated to the ETH Domain including ETH

Zurich, EPFL Lausanne, Empa and other federal

institutes. As the second important funding entity, the

Swiss Federal Office of Energy (SFOE) provides 16%,

followed by EU funds with 11%, the Cantons 9% and

the Commission for Technology and Innovation with

5%. The SFOE sponsors applied research projects,

including national contributions to the collaborative

R&D programmes of the International Energy Agency

(IEA).

The SFOE R&D programme 'Energy in Buildings'

aligns with the IEA Energy in Buildings and Com-

munities (EBC) programme. In its plan for the period

2013 - 2016, SFOE has defined five research areas:

– Building renovation has priority over new build-

ings: The challenge for the future lies in the refur-

bishment of the existing stock.

– Optimal use of technology: Technical improve-

ments to buildings service systems and envelopes

are able to contribute to energy demand reduc-

tion, but it is crucial to design and operate building

technologies in an optimal way.

– From a single building to urban areas: The 'system

boundary' should be expanded from buildings up

to building clusters, settlements or whole cities.

– The building as a 'storage power station':

Every building has the potential to produce ener-

gy through the use of energy from underground,

from the environment or from the roof. More than

this, they offer a variety of possibilities for energy

storage.

– Indirect energy consumption: Embodied energy of

the construction materials and occupant travel, as

well as occupant behaviour, all contribute to the

energy 'footprint' of buildings.

Energy research is facing the major challenge to

develop technologies and approaches to create a sus-

tainable energy sector over the coming years. The

buildings sector must bear the burden for a large part

of this task.

Further informationEnergy Strategy 2050, Federal Council, 2012,

www.bfe.admin.ch

54%

16%

11%

9%5% 5%

ETH Domain

SFOE

EU

Cantons16%

CTI

Other

Shares of public funding of energy-related r&d in Switzerland. Total annual funds are 214 million francs (about 180 million Euro).

Key areas of the Swiss federal energy policy

– Energy efficiency: reduction of energy consump-tion, predominately in the buildings sector.

– renewable energy: hydropower should be the main source of domestic renewable energy. The proportion of other renewable energy sources in the energy mix should be increased.

– large power stations: from 2020 some major power stations will be disconnected from the grid. Switzerland needs either to build new con-ventional large power stations, import more pow-er, or create a large number of smaller combined heat and power (ChP) installations.

– foreign energy policy: one of the key focuses of the energy strategy is to improve international co-operation, in particular with the Eu.

6 EBC Newsletter June 2013, Issue 57

Energy efficiency is a national political priority in

Italy, as in many other countries worldwide. To help

to stimulate achieving this goal, the Energy Efficien-

cy Action Plan has been agreed in 2007, which sets

ambitious targets for energy savings.

The existing building stock in Italy is generally energy

inefficient and much of it requires renovation. How-

ever, experience with this sector is already demon-

strating that financial mechanisms to support energy

efficiency policies are useful instruments at several

levels. These include mobilising funding for construc-

tion, providing economic support to end users, recog-

nising changing energy end uses mixes, supporting

market penetration of new technologies, and helping

to achieve targets through refurbishment.

Progress As required by EU Directives, an objective for a 10%

saving has been fixed compared with average energy

end use between 2001 and 2005. Actual energy end

use was 135 Mtoe (1570 TWh) in 2011, which is in

accordance with the Energy Efficiency Action Plan.

This represents a 3% reduction in primary ener-

gy consumption relative to 2010. This reduction is

believed to arise from the combined effect of the

economic crisis and of energy policies.

The success of energy efficiency policies is strongly re-

lated to the buildings sector, which uses most energy.

In this sector, the share of total energy use decreased

from 36% in 2010 to 34% in 2011. The national im-

plementation of the EU Energy Performance of Build-

ing Directive (EPBD) 2002 set high energy efficiency

standards for new buildings and for building renova-

tion, but these have not yet had a significant impact on

the sector. This is mainly due to the characteristics of

the building stock in Italy and to a lack of exploitation

of energy saving potential during building renovation.

The building stockThe Italian residential building stock consists of 29.6

million dwellings contained within 11.6 million in-

dividual buildings. Single and two family houses ac-

count for more than 40% of this stock. Large blocks

with more than 15 apartments account for the 10% of

the buildings and for the 23% of the dwellings. There

are approximately 150,000 non-residential build-

ings, with offices and schools accounting for the 80%

of the total. Around 30% of residential buildings and

20% of office and school buildings were built before

1945. 70% of the national stock was built before the

introduction of the first law on the energy efficiency of

buildings in the mid-1970s. Only 10% was construct-

michele Zinzi and gaetano fasano

Funding energy efficiency improvements to existing buildings by making them tax deductible has helped Italy to achieve their energy saving plans. Energy renovation is not taxing.

Financing Energy Renovation of Existing Buildings in Italy

20

30

40

50

60

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end

uses

, Mto

e

Non-residential buildingsResidential buildings

0

10

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

Evolution of energy end use in the buildings sector

EBC Newsletter June 2013, Issue 57 7

ed during the last 20 years, when improved energy

performance was legally required. In this regard, two

crucial issues have emerged:

– Much of the stock is obsolete and characterised by

poor energy performance, often coupled to other

safety aspects, such as static and environmental

hazards. As an example, more than 40,000 school

buildings have severe structural problems. A nat-

ional plan for retrofitting them is being developed,

so providing an important opportunity to include

energy retrofit measures.

– The rate of new building completion has been very

low during the last twenty years. This means that

even if energy standards for new buildings are

very strict, the impact on the whole sector would

not be significant for many years ahead. This im-

plies the energy performance of the existing stock

also has to be upgraded.

Energy end use in the buildings sectorThe implementation of energy efficiency policies has

had a positive impact for residential buildings. As a

consequence, while electricity use by space cooling

equipment and other appliances in the residential

sub-sector went up significantly between 1990 and

2010, overall energy use in this sub-sector did not

change appreciably over the same period.

In contrast, energy use increased by 140% in the

non-residential sub-sector, in which there has been

a significant growth both of stock size and of energy

use. While residential buildings accounted for 75% of

energy end use of the buildings sector in 1990, this

had decreased to 58% by 2010. The trend shows that

the two sub-sectors are likely to account for similar

total energy use in the next few years. A number of

further issues should be addressed by successful

energy policies:

– As a priority, heating energy use is critical for resi-

dential buildings, accounting for close to 70% of

overall use.

– As in many other industrialised countries, the

economy is increasingly service oriented. This

transformation impacts the building stock and its

related energy use.

– The non-residential sector and some specific

building categories are experiencing a noticeable

increase in electricity use for air conditioning.

Measures for energy retrofit of existing buildingsThe first law on the energy performance of buildings

was issued in 1976 and several others have been pro-

duced since then. Since this time attention has been

focused on heating energy use, as the most demand-

ing service. High heating energy use is a common

characteristic of the residential stock built before the

1970s, with improved performance in later construc-

tion.

Taking these factors into account, policy makers de-

cided to develop funding schemes to support the en-

ergy renovation of buildings. An important financial

scheme was launched in 2007, with a 55% tax deduc-

tion offered for energy saving measures in existing

buildings. The scheme is applicable to both individu-

als and companies. The measures are focused on

heating performance including the building envelope,

The odEx energy efficiency indicators are defined in various ways appropriate to end use and are expressed here relative to 1990 levels.

6065707580859095

100105

OD

EX

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ffici

ency

indi

cato

r

Year

Thermal usesElectric usesTotal

60

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

Year

Evolution of the ODEX energy efficiency indicators in the residential sector (1990 = 100)

8 EBC Newsletter June 2013, Issue 57

heat generators and renewable energy supplies. The

minimum requirements depend on the climatic zone,

with a fixed maximum cost for each measure.

In the latest Annual Energy Efficiency Report, it is

estimated the energy saving associated with the tax

deduction scheme is 7.6 TWh. Particularly during the

current financial crisis, the scheme is now considered

a necessity for end users, as well as for the industry

that it benefits. In fact, industry association stud-

ies have estimated it has generated a turnover of 11

billion Euros between 2007 and 2010, with an addi-

tional 4.5 billion Euros expected from 2011 to 2012.

The success of the 55% tax deduction scheme and a

separate PV funding scheme led to the implementa-

tion of another financial mechanism commencing in

2013. The scheme, called Conto Termico Energia, is

focused on the production of thermal energy by re-

newable energy systems and on energy efficiency im-

provements. Private entities are permitted access to

the financial mechanism relating to energy produc-

tion from renewable energy supply systems, which

includes heat pumps. In addition, solar cooling, an

emerging technology, is included. Relating to such

schemes, Italy is also involved in the EBC project,

'Annex 56: Cost Effective Energy and CO2 Emissions

Optimization in Building Renovation' to help to en-

sure they have a sound technical and financial basis.

Based on a public incentive of 7.9 billion Euros, a

gross turnover of 20 billion Euros is expected from

the scheme from 2012 to 2020. Moreover, it should

increase renewable thermal energy production from

7 ktoe per year in 2013 up to around 10 ktoe per year

by 2020. If successfully implemented, annual energy

savings from the scheme are expected to reach 1.6

Mtoe (19 TWh) per year by 2020.

ConclusionsThe national Energy Efficiency Action Plan for Italy

has set ambitious targets for energy savings in the

buildings sector. To this end, financial mechanisms

to underpin energy efficiency policies are useful

because:

– They mobilise investments even during severe

recessions, often providing the breadline for many

small and medium-sized companies operating in

the construction sector.

– They provide economic support to upgrade the

quality of their buildings for end users, who would

otherwise often be forced to occupy poorly per-

forming buildings.

– They recognise the increase in cooling demand.

– They support the market penetration of new tech-

nologies.

– They support the achievement of the national

energy saving targets through the refurbishment

of the existing building stock.

Further informationItalian Action Plan for Energy Efficiency, 2007,

Ministry of Economic Development

Energy Efficiency Annual Report, 2011, ENEA

www.efficienzaenergetica.enea.it

The evolution of energy demand over time is shown for space heating according to building typology. high energy use for the stock built before the 1970s is evident, as are the good standards achievable through legislation for dwellings constructed after 1976.

50

100

150

200

250

e he

atin

g en

ergy

con

sum

ptio

n kW

h/m

2ye

ar

Single family houseRow houseLarge apartment block

0

50

<190

0

1901

-192

0

1921

-194

5

1946

-196

0

1961

-197

5

1976

-199

0

1991

-200

5

>200

5

Spa

c e

Estimated energy consumption for space heating in residential buildings by construction period

EBC Newsletter June 2013, Issue 57 9

One of the most significant barriers to reducing build-

ing energy use is insufficient knowledge about the full

range of factors that determine it. The well-known

factors that have a direct influence include climate,

the building envelope, building services, indoor

environmental conditions and equipment. But, energy

use also depends on operation and maintenance and

occupant behaviour, the latter of which has not been

well understood. The recently completed internation-

al EBC project, 'Annex 53: Total Energy Use in Build-

ings: Analysis and Evaluation Methods' was therefore

established, with emphasis on improving knowledge

about occupant behaviour. The project objectives

were to:

– Define terminology, indicators and quantify in-

fluencing factors for energy use for two building

types (offices and residential buildings), particu-

larly to characterise occupant behaviour.

– Improve methodologies and techniques to monitor

total building energy use.

– Create new methodologies to analyse total build-

ing energy use and then investigate the factors

that influence this, including modelling of occu-

pant behaviour.

– Create methodologies to predict total energy use

in buildings and to assess the impacts of energy

saving policies and techniques, including the influ-

ence of occupant behaviour.

As a key contributor to total building energy use, the

role of occupant behaviour modelling within energy

performance evaluation has had close attention in the

project. This, in turn, has increased confidence in the

application of energy performance evaluation for indi-

vidual buildings and for stock analysis.

Modelling occupant behaviour and energy performance evaluationEnergy use both in residential and in office buildings

is influenced by the behaviour of occupants in various

ways. Such behaviour is related to actions controlling

building operation, as well as to household or other

activities. These actions and activities may be driven

by various factors. Occupants experience their physi-

cal environments due to their locations, biological and

psychological states, and by interactions with those

environments.

Concerning residential buildings, behaviour is affect-

ed by the presence of an occupant at a specific time

and location with access to specific building controls.

Beyond these, their building and appliance usage pro-

files, attitude to energy costs, and attention to mainte-

nance may each contribute to overall energy use. For

residential buildings, particular aspects of behaviour

relate to use of:

– heating,

– cooling,

– ventilation and windows,

– domestic hot water,

– appliances and electric lighting, and

– cooking.

The classification of energy-related occupant behav-

iour in office buildings requires three different levels,

namely:

1. individual occupant / manager level,

2. zone / office level, and

3. building level.

Total Energy Use in Buildings Completed Project: Annex 53

Prof hiroshi yoshino

Set your mind at rest, better models for occupant behaviour may lead to improved strategies and policies for energy savings in buildings.

10 EBC Newsletter June 2013, Issue 57

At each level, occupant and management behaviour

needs to be considered with respect to electric light-

ing, equipment, natural or mechanical ventilation,

and heating and domestic hot water systems.

As for modelling occupant behaviour, in general there

are two kinds that can help to:

– understand stimuli for the behaviour itself, and

– reveal its relationships with energy demand, usage

profiles and the underlying stimuli.

Energy performance evaluation carefully taking into

account occupant behaviour is intended to make

predictions based on building simulation tools more

robust. A systematic approach to this was developed

in the project based upon 'sensitivity analysis' of sim-

ulation results with respect to the influencing param-

eters. This can take place at two different points in

the building life-cycle, either at new build stage or in

operation.

At new build stage during the design phase, propa-

gation of input parameter uncertainties is quanti-

fied by finding sensitivity coefficients from simula-

tion results. Based upon this systematic procedure, a

'regression model' (linear or non-linear) is identified,

which can be used to estimate the performance of a

given design.

For an existing building in operation, the same type

of regression model may be used. In this case, certain

parameters may already be known accurately and

these should be fixed during the analysis. The perfor-

mance of a number of 'energy conservation measures'

can then be assessed.

Individual building and stock analysisA highly structured database has been defined in the

project, which has been used to collate information

about the influencing factors for building energy use.

This has been applied along with the terminology and

indicators developed to 12 office and 12 residential

building case studies. Based on the collated informa-

tion, the analyses performed can be divided into three

consecutive steps that require the use of: statistical

analysis to produce a clear description of the study

building; statistically based tools to identify the most

relevant factors influencing the building energy use;

statistically based methods to define and apply a suit-

able model to predict the building energy use.

The investigations have been focused at three differ-

ent scales, these being for:

– individual buildings,

– large building stocks, and

– regional or national level analyses.

When the study focuses on very large building stocks

(for regional or national analysis), useful evaluations

can be performed even if little information is avail-

able for each individual building. But, for a study

focusing on an individual building, the amount of re-

quired information increases, not least because data

about energy use and the corresponding influencing

factors have to be collected at monthly or shorter time

intervals.

Project outcomesBy combining expertise from organisations in 15 par-

ticipating countries, the project has generated new

knowledge about total building energy use that will

enable the development of new strategies and policies

for energy savings. The project outcomes include:

– guidance on how to apply statistical and analyti-

cal methods as predictive models for total energy

use, and

– documented building case studies, measurement

methods and total energy use data.

The project has improved understanding about mod-

elling occupant behaviour, and so has increased

confidence in the use of simulation for assessing to-

tal energy use for individual buildings and for large

building stocks.

Further informationwww.iea-ebc.org

EBC Newsletter June 2013, Issue 57 11

To achieve ambitious targets for non-renewable en-

ergy savings in the buildings sector in industrialised

countries, innovative energy supply technologies

must be applied. These should be highly efficient and

able to integrate renewable supply systems. For this

purpose, micro-generation offers good possibilities

to contribute to more sustainable energy supply sys-

tems. This has been the focus of the international EBC

research project 'Annex 54: Micro-Generation and

Related Technologies in Buildings'.

What is micro-generation?Micro-generation comprises of technologies for gen-

erating useable energy with small-scale systems of

up to around ten kilowatts capacity, such as photo-

voltaic systems or micro-wind turbines. The combined

production of heat and electrical power (CHP) in a

single small-scale process is called micro-cogen-

eration (µCHP). This can be extended to a micro

tri-generation system if cooling is produced in addi-

tion. A micro-cogeneration system consists of a high

efficiency unit to produce heat and power and typi-

cally several of the following components:

– a thermally or electrically driven cooling system

if required,

– a thermal storage buffer, used to decouple heat

and power and to increase µCHP runtime,

– an auxiliary burner for thermal peak load cover-

age,

– a supplementary electrical power generation sys-

tem, for example photovoltaics or a micro wind

turbine,

– a battery storage system to save surplus elec-

tricity and cover peak loads (for example using a

'second life' battery previously installed in an electric

vehicle),

– an electrical grid connection for surplus feed-in

and peak load coverage, or

– an advanced control system for optimal operation

of the components.

Technical developmentsState of the art µCHP systems are highly efficient due

to the use of otherwise waste heat from electricity

generation. The integration of thermal storage allows

temporal decoupling of electricity generation from

heat demand. Currently, µCHP systems are mainly

fuelled with natural gas, but LPG and fuel oil systems

are also available. Small-scale systems running on

renewable resources such as vegetable oil, biogas or

wood pellets are not yet commercially available.

Micro-Generation in BuildingsCompleted Project: Annex 54

Peter Tzscheutschler and Evgueniy Entchev

Small systems may have a big future. Micro-cogeneration used with energy storage and other technologies can help to balance supply and demand.

a 1 kW (electricity) µChP system including thermal storage.

12 EBC Newsletter June 2013, Issue 57

Technical performance

EconomicsEnvironmental

impactSystem

optimization

li i dPolicies and Regulations

Co-generators using conventional internal combus-

tion engines (ICE) at the scale of several hundred kilo-

watts are widely deployed. In the range of µCHP, ICE

co-generators with 1 kW to 5 kW electrical and up to

about 12 kW thermal output have been on the market

for about a decade. Small Stirling engine systems with

about 1 kW electrical output are new to the market

and are suitable for single family houses.

Fuel cell based µCHP systems have high electrical

efficiency with no moving parts and thereby low

maintenance requirements. The high power to heat

ratio of fuel cells fits well with the requirements of low

energy buildings with low heat demand, but still with

significant electricity use. Much development work on

fuel cell µCHP has been carried out, for instance in

Japan, where this technology is already on the mar-

ket. Meanwhile, these systems are also now available

in Europe and North America.

Besides the development of micro-generation com-

ponents, it is essential to focus on advanced control

systems. These would enable micro-generation tech-

nologies to act as active components in future smart

grids.

Smart local generationThe management of energy flows within buildings

and the ability to store thermal and electrical energy

will be of great importance in the future, when fluctu-

ating generation patterns including major renewable

energy sources will be expected to align with energy

demand profiles. Together with a building energy

management system, thermal and electrical storage

capacities, micro-generation offers possibilities to

locally match electrical power generation with

energy demands, but in an interconnected smart grid

environment.

Technology assessmentTo evaluate and optimize a system, technical

performance has to be determined and improved.

For micro-generation one key performance param-

eter is therefore the system efficiency. This is broadly

defined as the output of useful energy in terms of heat

and electricity in relation to the input of delivered

energy, in this case generally natural gas. Typically

at the moment, the electrical efficiency for µCHP lies

in the region of 25% for ICE systems, 15% for Stirling

engine systems and up to 50% for systems using fuel

cells. Also taking into account the generation of useful

heat can result in a total efficiency from 85% to 95%.

To determine its environmental impact in terms of

primary energy demand and greenhouse gas emis-

sions, a micro-generation system should be compared

with a conventional reference system. So, the charac-

teristics of the existing energy supply system have to

be taken into account, including large scale electrical

power generation and the relevant policy and regula-

tory framework. As these vary widely between differ-

ent countries, such an assessment can only be made

on a national basis. Nonetheless, recent results show

that depending on national circumstances, µCHP

systems are able to save up to 20% in terms of

primary energy and CO2-emissions compared to con-

ventional reference systems.

Further informationwww.iea-ebc.org

a schematic representation of the technology assessment process that can be used for system optimization.

EBC Newsletter June 2013, Issue 57 13

The 'embodied' energy and carbon dioxide (CO2) of

construction products are defined as the fossil fuel

energy use and the related CO2 emissions respectively,

arising during the entire process of:

– extracting and processing of raw materials,

– manufacture, and

– transportation.

Because building operational energy use is now being

reduced in many industrialised countries, embodied

energy (and similarly embodied CO2) is becoming in-

creasingly significant. Particularly for 'low carbon'

building design, the embodied CO2 may constitute a

large proportion of the whole life emissions encom-

passing the construction, operation and demolition

phases. Further to this, fractions of embodied energy

are already generally higher in developing than in

industrialised countries, where they often exceed the

building operational energy.

At present, a generally accepted methodology is

lacking for calculating embodied energy and CO2

for building construction. For this reason, the new

international EBC project, 'Annex 57: Evaluation of

Embodied Energy and Carbon Dioxide Emissions for

Building Construction' has been initiated. The pro-

ject was launched in 2012 and for benefit of building

designers is now developing:

– evaluation methods for embodied energy and CO2

emissions, and

– design and construction methods for buildings

with low embodied energy and CO2 emissions.

To date, efforts have been made to approximately

evaluate embodied energy and CO2 using information

from existing databases.

Embodied Energy and CO2New Project: Annex 57

Prof Tatsuo oka

Fossil fuel use needed to make construction products and deliver them to site is rapidly gaining attention. Embodied energy is material.

The corresponding fractions of embodied Co2 due to building construction and public works were estimated using an input-output analysis. Embodied Co2 was 19.2% of the total, while the operation of buildings was 23.2%.

50

60

70

80

90

100

Frac

tion

(%) Others (Industry &

Transportation)Energy for Non-Residential BuildingEnergy for Residential BuildingCivil Engineering

Repair of Constructions

CO2 due to Industry& Transportation

0

10

20

30

40 Non-residential ConstructionResidential Construction

Embodied CO2

Operation CO2

Annual fraction of embodied CO2 of total emission in Japan (1.29 Billion tonnes CO2 in 2005)

14 EBC Newsletter June 2013, Issue 57

The 'gate factory' is the final factory in the supply chain for a construction product. The energy use in the gate factory is small compared with the total embodied energy, and therefore shows that the embodied energy of input materials into each gate factory should be estimated accurately.

Database selection Two alternative types of database of embodied energy

and CO2 for building construction materials have pre-

viously been compiled. These are both widely used

and are based on either:

– the International Organization for Standardization

(ISO) methodology, or

– 'input-output' (IO) analysis.

It is considered that ISO-based databases tend to

reflect manufacturing efficiencies rather than the

embodied energy and CO2 due to building construc-

tion. Although databases compiled using IO analy-

sis would seem to be more relevant, from a practical

standpoint fewer building components are contained

within them than in the ISO-based databases.

Building materials and components Key materials and components used in building con-

struction may include: concrete, steel, wood, brick,

external surface materials, glazing and framing

materials, insulation, floor surfaces, ceiling and inner

surfaces of the exterior walls, or fixed building servic-

es systems (electrical systems including distribution,

building management, IT and security, electric light-

ing; HVAC; hot and cold water supply and foul drain-

age; indoor transportation).

Since a building typically consists of several hundred

components, reducing the number of components, if

possible, would decrease embodied energy and CO2.

Moreover, since the total embodied energy used in the

building is equal to the value of the embodied energy

intensity multiplied by the quantity of materials, the

latter is an important factor.

Achieving designs with low embodied energy and CO2 emissions Thus far in the project, approximate estimations have

been made to find the significant factors for reducing

embodied energy and CO2.

At an early design stage, building designers need to

compare the embodied energy and CO2 with bench-

marks for the proposed construction to examine the

impact of its form and features. Since approximately

90% of the building performance is determined in the

initial design stages, designers can benefit from case

studies that show how embodied energy and CO2 can

be reduced. Therefore, these will be produced by the

participating countries in the project.

Design and construction methods for buildings with

low embodied energy and CO2 are being improved by

the use of recycled materials, prolongation of building

life, retrofitting, and also reduction of non-CO2 green-

house gas emissions. In fact, 60% of global warming

overall has been calculated to be due to CO2 emission,

but with a further 14% attributed to Freon gases,

which in some countries still are used in insulation

materials and in electric refrigerators.

Further informationwww.iea-ebc.org

Energy consumption in industrial sector (%)

industrial Sector Cement product hot rolled steel air con non wooden building

Cement 32.4 0.0 0.1 5.5

Cement products 18.7 0.0 0.0 0.4

Pigiron 11.4 78.9 21.6 27.4

hot rolled steel 0.9 5.9 1.2 2.0

Cast and forged materials 0.0 0.0 3.0 0.2

air conditioning equipment 0.0 0.0 5.9 0.0

non wooden building 0.0 0.0 0.0 6.4

Electricity supply 15.4 6.2 33.8 16.0

Total 78.8 91.1 65.5 57.9

Fraction of embodied energy of building components at the gate factory

EBC Newsletter June 2013, Issue 57 15

Annex 5 Air Infiltration and Ventilation CentreThe aivC carries out integrated, high impact dissemination activities with an in depth review process, such as delivering webinars, workshops and technical papers.Contact: dr Peter WoutersE: aivc@bbri.be

Annex 51 Energy Efficient CommunitiesThe project is specifically targeting local decision makers and stakeholders, who are not experts in energy planning. Guidance, case studies and a decision making tool are being produced to assist in implementing robust based approaches. Contact: Reinhard JankE: reinhard.jank@Volkswohnung.com

Annex 52 Towards Net Zero Energy Solar Buildings (NZEBs)The project is achieving a common understanding of net-zero, near net-zero and very low energy buildings concepts and is delivering a harmonized international definitions framework, tools, innovative solutions and industry guidelines.Contact: Josef AyoubE: Josef.Ayoub@RNCan-NRCan.gc.ca

Annex 53 Total Energy Use in Buildings: Analysis and Evaluation MethodsImproved knowledge of the influence of different factors on energy use in buildings, particularly occupant behaviour, is essential to accurately assess short- and long-term energy saving measures, policies and technologies. The beneficiaries of the work are policy makers, energy services contracting companies, manufacturers and designers.Contact: Prof Hiroshi YoshinoE: yoshino@sabine.pln.archi.tohoku.ac.jp

Annex 54 Integration of Micro-generation and Related Energy Technologies in BuildingsA sound foundation for modelling small scale co-generation systems underpinned by extensive experimental validation has been established to explore how such systems may be optimally applied.Contact: Dr Evgueniy EntchevE: eentchev@nrcan.gc.ca

Annex 55 Reliability of Energy Efficient Building Retrofitting - Probability Assessment of Performance and Cost The project is providing decision support data and tools concerning energy retrofitting measures for software developers, engineers, consultants and construction product developers. Contact: Dr Carl-Eric HagentoftE: carl-eric.hagentoft@chalmers.se

Annex 56 Cost-Effective Energy and CO2 Emission Optimization in Building RenovationThe project is delivering accurate, understandable information and tools targeted to non-expert decision makers and real estate professionals. Contact: Dr Manuela Almeida E: malmeida@civil.uminho.pt

Annex 57 Evaluation of Embodied Energy and CO2 Emissions for Buil-ding ConstructionThe project is developing guidelines to improve understanding of evaluation methods, with the goal of finding better design and construction solutions with reduced embodied energy and related CO2 emissions.Contact: Prof Tatsuo OkaE: okatatsuo@e-mail.jp

Annex 58 Reliable Building Energy Performance Characterisation Based on Full Scale Dynamic MeasurementsThe project is developing the necessary knowledge, tools and networks to achieve reliable in-situ dynamic testing and data analysis methods that can be used to characterise the actual energy performance of building components and whole buildings. Contact: Prof Staf RoelsE: staf.roels@bwk.kuleuven.be

Annex 59 High Temperature Cooling and Low Temperature Heating in BuildingsThe project aim is to improve current HVAC systems, by examining how to achieve high temperature cooling and low temperature heating by reducing temperature differences in heat transfer and energy transport processes.Contact: Prof Yi Jiang E: jiangyi@tsinghua.edu.cn

Annex 60 New Generation Computational Tools for Building and Community Energy Systems Based on the Modelica and Functional Mockup Interface StandardsThe project is developing and demonstrating new generation computational tools for building and community energy systems based on the non-proprietary Modelica modelling language and Functional Mockup Interface standards.Contact: Michael Wetter, Christoph van TreeckE: mwetter@lbl.gov, treeck@e3d.rwth-aachen.de

Annex 61 Development and Demonstration of Financial and Technical Concepts for Deep Energy Retrofits of Government / Public Buildings and Building ClustersThe project aims to develop and demonstrate innovative bundles of measures for deep retrofit of typical public buildings to and achieve energy savings of at least 50%. Contact: Dr Alexander M. Zhivov, Rüdiger Lohse E: Alexander.M.Zhivov@erdc.usace.army.mil, ruediger.lohse@kea-bw.de

Annex 62 Ventilative Cooling This project is addressing the challenges and making recommendations through development of design methods and tools related to cooling demand and risk of overheating in buildings and through the development of new energy efficient ventilative cooling solutions.Contact: Per HeiselbergE: ph@civil.aau.dk

EBC International ProjectsCurrent Projects

16 EBC Newsletter June 2013, Issue 57

CHAIRAndreas Eckmanns (Switzerland)

VICE CHAIRDr Takao Sawachi (Japan)

AUSTRALIAStefan PreussE: Stefan.Preuss@sustainability.vic.gov.au

AUSTRIAIsabella Zwerger E: Isabella.Zwerger@bmvit.gv.at

BELGIUMDr Peter WoutersE: peter.wouters@bbri.be

CANADA Dr Morad R AtifE: Morad.Atif@nrc-cnrc.gc.ca

P.R. CHINAProf Yi Jiang E: jiangyi@tsinghua.edu.cn

CZECH REPUBLICTo be confirmed DENMARKRikke Marie HaldE: rmh@ens.dk

FINLANDDr Markku J. VirtanenE: markku.virtanen@vtt.fi

FRANCEPierre HérantE: pierre.herant@ademe.fr

GERMANYMarkus Kratz E: m.kratz@fz-juelich.de

GREECETo be confirmed

IRELANDProf J. Owen LewisE: j.owen.lewis@gmail.com

ITALYDr Marco CitterioE: marco.citterio@enea.it

JAPANDr Takao Sawachi (Vice Chair)E: tsawachi@kenken.go.jp

REPUBLIC OF KOREADr Seung-eon Lee E: selee2@kict.re.kr

NETHERLANDSPiet HeijnenE: piet.heijnen@agentschapnl.nl

NEW ZEALANDMichael DonnE: michael.donn@vuw.ac.nz

NORWAYEline SkardE: eska@rcn.no

POLANDDr Beata Majerska-PalubickaE: beata.majerska-palubicka@polsl.pl

PORTUGALProf Eduardo MaldonadoE: ebm@fe.up.pt

SPAIN José María Campos E: josem.campos@tecnalia.com

SWEDEN Conny RolénE: conny.rolen@formas.se

SWITZERLANDAndreas Eckmanns (Chair)E: andreas.eckmanns@bfe.admin.ch

UKClare HanmerE: Clare.Hanmer@carbontrust.co.uk

USARichard KarneyE: richard.karney@ee.doe.gov

EBC Executive Committee Members

IEA Secretariatmark lafranceE: marc.lafranCE@iea.org

EBC Secretariatmalcolm ormeE: essu@iea-ebc.org

www.iea-ebc.org